Morphology Flashcards
1
Q
Virion
A
Virus outside of a cell
2
Q
Morphology of a virion
A
- Core: Nucleic acid + proteins
- Capsid: Proteins
- ± Envelope: Lipid membrane + proteins
3
Q
How are virions examined?
A
By electron microscopy
- Negative contrast staining
- Uranyl acetate
- When viewing the surface
- Shadow casting
- Au vapour
- Pt vapour
- Pl vapour
4
Q
What is shown
A
Shadow staining
- Different angles of light give different shadows
5
Q
Capsomers
A
Capsid is composed of protein units
6
Q
Nucleic acid + capsomer =
A
Nucleocapsid
7
Q
Quasihelical viruses
A
- Orthomyxo-, Paramyxo-, Rhabdovirus
- Enveloped
8
Q
Icosahedral virus
A
- 20 equilateral triangle
- Proteins arranged into capsomers
- Adeno-, parvovirus
- May have an envelope:
- Herpesvirus
- Flavivirus
9
Q
Binal virus
A
- Icosahedral head, helical tail
- Tailed bacteriophages
10
Q
Complex virus
A
- Poxvirus
- No capsomers
- Complicated symmetry
11
Q
Pleomorphic virus
A
- Arenavirus
- G-type phages
- No capsid
- Always enveloped
